On 12/20/22 13:11, Thomas Zimmermann wrote:
> RGB888 is different than the other formats as most of its pixels are
> unaligned and therefore helper functions do not use endianness conversion
> helpers. Comment on this in the source code.
>
> Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
Reviewed-by: Maíra Canal <mcanal@xxxxxxxxxx>
Best Regards,
- Maíra Canal
> ---
> drivers/gpu/drm/drm_format_helper.c | 1 +
> drivers/gpu/drm/tests/drm_format_helper_test.c | 4 ++++
> 2 files changed, 5 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_format_helper.c b/drivers/gpu/drm/drm_format_helper.c
> index 74ff33c2ddaa..b98bd7c5caee 100644
> --- a/drivers/gpu/drm/drm_format_helper.c
> +++ b/drivers/gpu/drm/drm_format_helper.c
> @@ -404,6 +404,7 @@ static void drm_fb_xrgb8888_to_rgb888_line(void *dbuf, const void *sbuf, unsigne
>
> for (x = 0; x < pixels; x++) {
> pix = le32_to_cpu(sbuf32[x]);
> + /* write blue-green-red to output in little endianness */
> *dbuf8++ = (pix & 0x000000FF) >> 0;
> *dbuf8++ = (pix & 0x0000FF00) >> 8;
> *dbuf8++ = (pix & 0x00FF0000) >> 16;
> diff --git a/drivers/gpu/drm/tests/drm_format_helper_test.c b/drivers/gpu/drm/tests/drm_format_helper_test.c
> index 2191e57f2297..cd1d7da3483c 100644
> --- a/drivers/gpu/drm/tests/drm_format_helper_test.c
> +++ b/drivers/gpu/drm/tests/drm_format_helper_test.c
> @@ -407,6 +407,10 @@ static void drm_test_fb_xrgb8888_to_rgb888(struct kunit *test)
> KUNIT_ASSERT_NOT_ERR_OR_NULL(test, xrgb8888);
> iosys_map_set_vaddr(&src, xrgb8888);
>
> + /*
> + * RGB888 expected results are already in little-endian
> + * order, so there's no need to convert the test output.
> + */
> drm_fb_xrgb8888_to_rgb888(&dst, &result->dst_pitch, &src, &fb, ¶ms->clip);
> KUNIT_EXPECT_EQ(test, memcmp(buf, result->expected, dst_size), 0);
> }
